1, flow rate is one of the important performance data of pump selection, which is directly related to the production capacity and transportation capacity of the whole device. For example, the design institute can calculate the normal, small and large flow of the pump in the process design. When selecting a pump, it should be based on large flow and give consideration to normal flow. When there is no large flow, it is usually 1. 1 times the normal flow.
2. The lift required by the device system is another important performance data for selecting the pump. Pump selection generally adopts the lift after the margin is enlarged by 5%~ 10%.
3. Liquid properties, including the name, physical properties, chemical properties and other properties of liquid medium. Physical properties include temperature c, density d, viscosity u, solid particle diameter and gas content in the medium. This involves the head of the system, the calculation of effective cavitation allowance and the appropriate pump type: chemical properties mainly refer to the chemical corrosiveness and toxicity of liquid media, which is an important basis for selecting pump materials and shaft seal types.
4. The pipeline layout conditions of the device system refer to data such as liquid conveying height, liquid conveying distance, low liquid level at suction side and high liquid level at discharge side, pipeline specifications and their lengths, materials, pipe fittings specifications and quantities, etc. In order to calculate the carding head and check the cavitation allowance.
5. There are many operating conditions, such as liquid operation T, saturated steam force P, suction side pressure PS (), discharge side container pressure PZ, altitude, ambient temperature, whether the operation is intermittent or continuous, and whether the position of the pump is fixed or movable.